The egg tunnels of Henan

One interesting aspect of the Xixia dinosaur park and museum is that the site actually covers what must have been a dinosaur nesting ground. As with the Zigong Dinosaur Museum which built a museum over the actual fossil layer (and something similar is being constructed in Shandong at the moment) the decision was made to display these in situ and allow visitors to see them as they appear in the rock. However whereas in the case of the former the obvious thing to do was to expose the bones and build a platform over them, here the eggs are deep underground. The solution? Tunnel into the hillside and expose them from below!

So here you enter a tunnel network that twists and turns and with clusters of eggs hanging from the ceiling. As you can (hopefully) see, these are all in clusters which suggest nests and are all of the same size and shape and present in similar numbers which suggests they are also probably from a single species nesting together. The tunnels dip and rise in various places, but then the rocks are often at odd angles so it’s impossible to tell if the eggs are in a single horizon or scattered over a number of beds, but I would suggest that their similarity and proximity suggest that even if they are in different layers these were over potentially a narrow band of time and may well still represent a nesting site for a single species. What that animal may have been we don’t know since there are no embryos known and the science of dinosaur eggs is pretty tricky with some considerable variation seen in shape and structure even in constrained clades, and little has been done on these. They do look like small sauropod eggs, but would easily be from an ornithischian or a theropod, so don’t bank on that.

One thing for sure is that we need more research done on this site. Where dinosaur eggs arise they are often common but they are still rare in general and more research is needed. If we can work out which eggs go with which clades there is important new information to be gleaned from them and sites like this where there are hundreds of eggs potentially from dozens of nests of a single species can really tell us about sociality, behaviour and the reproductive biology of dinosaurs.